Actually I also do not know much.
I’m just trying to re-implement this thing in Zig, but currently with no any success.
And at the moment I tend to believe, zig/(or llvm?..) is not completely ready for 8-bit AVR.
Yes, you can write something working, but I’m not sure about complex programs.
See also this topic
There is Microzig project, but currently I do not want to use no HALs/frameworks,
so can’t say much about it.
Also, there is an (open) issue
No answer to the question in the most recent comment.